Its not that Yahoo hates sony, they are just using logic, right now Sony is in a fairly distant 3rd (further back from 2nd than the Gamecube ever was) and sales are beginning to decline.
They are just predicting it because they know that the PS3 needs it, so their is a good chance their prediction will be right, (sometimes these things become a self fullfilling prophecy)
the 360? Doing fine, but if the PS3 cuts they have the leverage to undercut them again.
End of 2009 Predictions (Set, January 1st 2009)
Wii- 72 million 3rd Year Peak, better slate of releases
360- 37 million Should trend down slightly after 3rd year peak
PS3- 29 million Sales should pick up next year, 3rd year peak and price cut